CHANGES IN VISUOSPATIAL ATTENTION OVER THE ADULT LIFE-SPAN

Shifts of visual attention elicited by spatial cues were examined for detection and letter-discrimination tasks in 90 normal adults ranging in age over each decade from the 20s to the 70s. Spatial cues were val id, invalid, or neutral in indicating probable target location and wer e presented either centrally at fixation or peripherally 6.7 to the le ft or right of fixation. Stimulus-onset asynchrony (SOA) between cue a nd target was varied between 200, 500 and 2000 msec. Reaction time (RT ) costs and benefits associated with spatial cueing did not vary with age for: (1) the detection task; (2) the letter-discrimination task wi th peripheral cues; and (3) the letter-discrimination task with centra l cues at a short (200 msec) SOA. RT costs and benefits increased with age only for SOAs greater than 200 msec with central cueing in the di scrimination task. In general, the efficiency of cue-based shifts of v isuospatial attention appears relatively resistant to the effects of a dult age up to 79 years. When an age effect was found. RT costs and be nefits increased steadily across all age decades, the correlation with age being 0.25 and 0.38 for the 500 and 2000 msec SOAs, respectively. The findings suggest a qualitative difference in the influence of nor mal adult aging and effects of dementia noted in previous studies; nor mal aging has only a weak influence on voluntary attention shifts, whe reas dementia affects both voluntary and involuntary modes of attentio n shifting.